In a conventional umbrella the upper ends of ribs are pivotally connected to the upper end of a shaft and the outer ends of stays or struts are pivotally connected to the ribs intermediate their length while the inner ends are pivotally connected to a sleeve which is slidable on the shaft between a closed position in which the ribs and stays lie alongside the shaft and an open position in which the stays support the ribs in extended position. The ribs are usually flexible and the cover is made-up of a number of sector-shaped portions corresponding to the number of ribs and is fashioned so that the ribs are bowed when in open position. When the umbrella is in closed position, the cover lies in loose folds around the shaft. In order to make the umbrella look somewhat neater when closed, a small strap is attached to the cover near its periphery so that the folds of the cover can be wrapped around the shaft and ribs and secured by the strap.
It has also been proposed to connect the inner ends of ribs of an umbrella pivotally to the upper end of a rod which is longitudinally movable in a tube. The inner ends of stays are pivotally connected to a slide which is longitudinally slidable on the rod and urged downwardly by a spring. The rod is moved longitudinally in the tube by means of an external sleeve connected to the rod by a bridge extending through a slot in the tube. When the rod is moved upwardly so that it projects above the tube, the stays support the ribs in extended position much as in a conventional umbrella. When the rod is moved downwardly to the lower end of the tube, the stays, ribs and cover are retracted into the tube. While of neater appearance in closed position than a conventional umbrella, the construction is somewhat complex so that it is more expensive to construct and less dependable in its operation. Moreover, in open position it suffers from the same defect as a conventional umbrella in that it can be turned inside out by the wind.
In U.S. Pat. No. 4,084,600 there is disclosed an umbrella comprising an elongated tubular shaft having upper and lower ends and a longitudinally extending slot. A rib carrier is longitudinally movable in the shaft by means of a handle which extends out through the slot. The upper end portion of the rib carrier is slotted to receive and guide inner end portions of ribs which are pivotally connected to the carrier. By means of the externally projecting handle, the rib carrier is movable longitudinally in the shaft between a closed position in which the rib carrier is near the lower end of the shaft and the ribs are in the shaft and an open position in which the rib carrier is at the upper end of the shaft and the rib members radiate out from the rib carrier and are approximately normal to the shaft. A flexible fabric cover, which is preferably formed of two-way stretch fabric, is secured at its center to the rib carrier and at its periphery to the outer ends of the rib members. In order to be wholly received in the shaft when the umbrella is in closed condition, the ribs have a length slightly shorter than the length of the shaft.